Vol. XII. No. 300. 



THE AGRICULTURAL NEWS 



3i: 



AGRICULTURAL ENGINEERING. 



DRAINING LAND TO FREE IT FROM SALT. 



It may be remembeied that in a recent issue of the 

 AgriniUiind News, an article appeared describing investiga- 

 tioD.s that had been carried out in Porto Rico in regard to 

 the eftect of common salt on the growth of sugar cane, and 

 the improvement of the large tracts of land in that island 

 which are at present unsuitable for cultivation purpose.s owing 

 to the high salt content. In connexion with this article, 

 another dealing with a new system for draining land and 

 freeing it from salt, which has appeared in the Monthl;/ 

 lliillitin of Act ricult II lal Intelliijence and Plant Diseases 

 (August 1913), contains information of much practical 

 importance. 



The system of drainage about to Be'described is appli- 

 cable wherever the surface of the soil is somewhat higher 

 than the water in the main drainage canal, so as to allow 

 a good drainage of the surface water without, however, 

 allowing a good drainage of the sub.soil. 



The principle of the system will be more clearly under- 

 stood by reference to the following diagram, which has been 

 reproduced from the journal acknowledged above. 



Fig. 26. Cross-section of New Dk.^inaue System kor 

 Freeing Lanij from S.\lt. 



The surface drainage water flows into the main drain- 

 age canal a where it is carried away by gravity. Into 

 the canal i run wooden or iron drains, represented by 

 the dotted line, which carry away kom the subsoil the 

 rainfall which percolates into it from above. The water in 

 f> is got rid of by means of a pump. 



In the field, the surface water is collected by means of 

 drainage ditches, which must be at least 36 inches deep and 

 about 100 feet apart, the distance depending upon the 

 mechanical and physical properties of the soil. In order to 

 calculate the power of the pumps required, it is necessary to 

 know the amount of water drained per acre and per day. 

 The formulae of Slichter and of King allow an approximate 

 estimation to be made of the cjuantity of water that can 

 percolate through the soil in a given time. 



In regard to the results that have recently been obtained 

 in connexion with this system in Lower Egypt, the amount 

 of water removed was only onebalf to two-fifths of that 

 which would have to be pumped according to ihe usual .system. 

 The important point, of course, is that the water removed is 

 ten to 100 times richer in salt than that removed by surface 

 drainage. 



Owing to the somewhat larger number of ditches 

 the system just described incurs somewhat greater expen.se 

 than the usual system of drainage. The expenses of installa- 

 tion and upkeep are also heavier; the ditterence, however, 

 is not considerable. The loss of cultivable area is between 

 2 and 3 per cent. The increase in the upkeep rarely exceeds 

 5 to 10 per cent. The greater expense on installation is 

 about 13.« to 14s. 6rf. per acre if woodeo pipes are u.sed, 

 and 10.S-. to •_'!.«. if iron cnes are employed. 



TRIALS WITH TRACTORS AND MOTOR. 

 PLOUGHS IN SOUTH AFRICA. 



A short time ago an editorial and several shorter articles 

 in this journal were devoted to motor cultivation, conse- 

 (jnently the results of the recent trials conducted during- 

 >"Tarch 1913 near Port Elizabeth, appearing in the KUod'-itia 

 Ae/riciiltnra/ Journal for August 1913, should afford an 

 interesting continuation of the subject 



The following tractors competed in the trials: 24b.h.p. 

 'Ivel' Agricultural Motor, price £450; 30 60 b.h.p. Rumely 

 'Oil Pull', type 'E', price £935; 18-20 b.h.p. 'Universal' 

 Tractor, price £375; 50 b h.p. Maclaren's 'Royal' Steam 

 Tractor, price £690; 15-25 b.h.p. Fairl>ank's Moss Oil 

 Tractor, price £568; 30-40 b.h p. Ransom's Special Agri- 

 cultural Steam Tractor, price £725; 30-50-60 b.h.p. Self- 

 steering Agricultural Oil Motor Tractor, price £950; 25 b.h.p. 

 'Mogul' Tractor, price £550. 



Early in the trials it was realized that difKculties had 

 to be confronted in judging, on account of the variation in 

 power. The comparison between the respective merits of 

 steam and oil tractors is also con.sidered to be a difficult 

 one in South Africa on account of the variation in regard to 

 the proximity of .sources of fuel and water supply. 



After a lengthy trial the judges unanimously decided 

 to award the prize of £100 to the makers of the 50 b.h p. 

 'Hoyal' Steam tractor, and a special prize of 25 guineas to 

 the manufacturers of the 18-20 b.h.p. 'Universal' Tractor. 



The following information with reference to the winning- 

 tractors may be of interest: — 



'Royal'. 'Universal'. 



Total area ploughed 2 acre.i i acre 



Time per acre 28 minutes 1 hr. 23 min. 



Fuel consumed per acre 80 tt>. Natal coal petrol 2 pints 



parafHn 3§ gals. 

 Water evaporated 



per acre 5U gallons Not measure* 

 Average depth of 



ploughing 8^ inches 7 inches 

 Radius of turning 



circle 16 feet 5 inches 12 feet 

 Number of bottoms 



to plough 8 2 



In making the awards, the judges call attention to the 

 outstanding feature of the prize-winning machines. Th* 

 characteristic feature of the 'Royal' steam tractor was it.<j 

 remarkably low consumption of fuel. This is said to be due 

 largely to the provision of a superheater, a feed water heater,^ 

 and the lagging of the steam cylinders and valve chests, 

 coupled with the fact that the engine was compound, i.e. 

 steam being passed through two cylinders in place of being: 

 pas.sed through one only. It has to be rememberd that against 

 these advantages are the difficulties due to getting up steant 

 and the transport of coal and water. In c annexion with the 

 'Universal' oil tractor, the judges made a satisfactory report 

 but suggested that all the gear should be enclosed and better 

 provision made for cooling and circulating water so necessary- 

 in a hot climate. The disadvantage of the 'Ivel' agricul- 

 tural motor con.sisted principally in its being provided with, 

 only one speed gear and a single road wheel too small in_ 

 diameter. In general, the chief objection to the oil- 

 consuming motors seemed to be exposure of gearing, 

 cooling arrangements, and the want of two or three- 

 speed gears in the place of one. It will lie remembered that 

 this latter point was emphasized in an editorial in this- 

 journal dealing with motor cultivation in general. 



